In this pasta with marinara sauce dish, are the instructions for the easy marinara sauce.
In a saucepan, saute the onions, but do not let them brown.
To the saucepan, add the liquid drained from the diced tomatoes. Add the basil, Italian seasonings, sugar (or sugar substitute) and crushed red peppers. Simmer liquid and spices for about 30 minutes without a lid or until liquid is reduced by half.
Add the diced tomatoes and crushed tomatoes and cook just until heated, about 1 minute.
Cook the pasta al dente.
Serve with marinara sauce.